In an automatic warehouse, articles are often transferred from a pallet for a single-article to a pallet for shipment (a transferring pallet). The pallet for a single-article is one type of articles stacked thereon, such as a plurality of the same article interlock-stacked. Said interlock-stacking stacks different layers of articles in different manners, is often used for shipment from a plant and so on, and is preferable when each type of a large number of articles is stocked in an automatic warehouse. Thus, articles are generally interlock-stacked on the pallet for a single-article. Most of the pallets to which the articles are transferred are used to mount thereon articles to be shipped from the automatic warehouse, and a single or plural types of articles may be loaded thereon. There are known apparatuses in which a pallet for a single-article and a transferring pallet are placed on an elevation means such as a lifter, and in which a carriage travelling on a transfer path such as rails picks up one layer of articles at a time from the pallet for a single-article to transfer them to the transferring pallet. This apparatus, however, interlock-stacks the articles if they have been interlock-stacked on the pallet for a single-article. This is because this apparatus only transfers one layer of articles at a time from the pallet for a single-article to the transferring pallet and because it does not have a means for changing the direction of the articles.
Interlock-stacking is likely to prevent the articles from collapsing, but is not suitable for manual unloading. This is due to the different directions of different layers (stages) of articles. Interlock-stacking includes brick stacking, alternate stacking, pinwheel stacking, and split stacking, and is characterized by the differing arrangements of vertical lines in different layers, which can be viewed from the side of the articles. On the contrary, bar stacking, which is simple stacking in which all layers of articles are arranged in the same direction, is likely to cause the articles to collapse and is not suitable for massive transfers, but is suitable for small-size transfers due to its convenience for manual unloading.
An object of the present invention is to automatically bar-stack articles interlock-stacked on a pallet for a single-article to allow them to be transferred to a transferring pallet.
An additional object of the present invention is to enable articles to be transferred from a pallet for a single-article to a transferring pallet at a high speed.
A further additional object of the present invention is to enable it to be easily determined whether articles on a pallet for a single-article to be transferred next belong to an odd- or even-numbered layer, in order to enable bar stacking to be maintained even when articles are transferred from a plurality of pallets for a single-article.